A cellular network consists of multiple base stations, each of which has a coverage area. Mobile devices, such as cellular phones, smart phones, tablets, and portable computers, wirelessly connect to these base stations to receive services such as data and voice connectivity. The extent of the coverage of a cellular network is defined by the reach of the individual base stations in the network and by the configuration of those base stations. Physical design considerations, such as transmission power, base station location, and antenna angle, play a significant role in determining the extent of a cellular network's coverage. In the past, a network provider could determine the extent and effectiveness of its network coverage only by sending technicians or testers into the field to test the coverage (e.g., the strength of signal) at particular locations. End users had little opportunity to participate in improving the network, except by complaining to customer service representatives. However, because of the large geographical extent of these cellular networks, it is difficult and expensive for network providers to perform extensive network testing by themselves. For this reason, standards organizations have recently developed mechanisms for using customers' mobile devices to collect network information that can be used to evaluate network effectiveness. However, designing this data collection mechanism is complicated because it is difficult to effectively collect data without also wasting significant amounts of power.